Method for producing stainless steel powder containing nitrogen high nitrogen by adopting gas atomization method

Abstract

The invention belongs to the field of powder metallurgy, in particular to a method for preparing nitrogen-containing / high-nitrogen stainless steel powder by gas atomization. Including the distribution of ingredients according to the alloy design; placing granular or massive high-nitrogen alloys in the secondary feeder, and feeding the rest of the ingredients into the melting furnace; melting in a vacuum and / or non-vacuum atmosphere; molten steel is obtained by stirring after melting Add high-nitrogen alloy to molten steel with uniform composition; heat up to 1500°C-1750°C to start atomization, the atomization medium is nitrogen, and the pressure is 1.0-10MPa; after the powder is cooled, it is screened and vacuum-packed as required. The invention has the characteristics of relatively simple equipment, easy operation, high production efficiency and low cost, and can produce stainless steel powders of different alloy systems with high purity, controllable nitrogen content and good fluidity.

Description

technical field [0001] The invention belongs to the field of powder metallurgy, in particular to a method for preparing nitrogen-containing / high-nitrogen stainless steel powder by gas atomization. Background technique [0002] In the late 1930s and 1940s, the shortage of nickel resources stimulated the research on the preparation of stainless steel by substituting nickel with nitrogen. The researchers found that nitrogen can not only improve the strength of steel materials, but also has an important effect on improving the corrosion resistance of materials, especially the resistance to chloride ion pitting corrosion. In addition, foreign studies in recent years have shown that nickel ions are a potential sensitizing factor, which can induce toxic effects, cell destruction and inflammatory reactions near implants in living organisms, and are teratogenic and carcinogenic to living organisms. 10-20% of women and 6% of men in the US and Europe are affected by nickel ions. ([1]...

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Problems solved by technology

[0010] The disadvantage of high-pressure nitrogen smelting-nitrogen atomization method is that high-pressure equipment is required, and there are disadvantages such as expensive and complicated equipment, high-pressure danger, difficult process control and high production cost.

[0011] The disadvantage of the fluidized bed powder nitriding method is that the microstructure of the nitriding powder is uneven, the oxygen content is high, and the energy consumption is high; the disadvantage of the mechanical alloying method is that the powder morphology is lamellar, the fluidity is poor, and the nitrogen content is not easy to control

[0012] In order to solve the problems in the production of nitrogen-containing stainless steel, such as expensive and complex equipment, high-pressure danger, difficult process control, high production cost, and poor powder fluidity, and to avoid other problems in the preparation of nitrogen-containing / high-nitrogen stainless steel powder, the present invention proposes a Method for preparing nitrogen-containing / high-nitrogen stainless steel powder by gas atomization process

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